Apparatus and process for active pulse intensity control of laser beam
First Claim
1. An optically controlled laser beam pulse energy regulation apparatus for a pulsed laser beam comprising:
- (a) photodetection means;
(b) means for directing a first portion of said pulsed laser beam onto said photodetection means to vary the resistance of said photodetection means in proportion to the energy of said beam;
(c) light intensity controlling means through which a second portion of said pulsed laser beam passes;
(d) means for integrating the beam energy incident on said photodetection means to generate a control voltage proportional to the beam energy to said light intensity controlling means; and
(e) optical delay means through which said second portion of said laser beam passes before entering said light controlling means;
whereby a control voltage is applied to said light intensity controlling means which is proportional to the amount of light energy striking said photodetection means.
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Accused Products
Abstract
An optically controlled laser pulse energy control apparatus and process is disclosed wherein variations in the energy of a portion of the laser beam are used to vary the resistance of a photodetector such as a photoresistor through which a control voltage is fed to a light intensity controlling device through which a second portion of the laser beam passes. Light attenuation means are provided to vary the intensity of the laser light used to control the resistance of the photodetector. An optical delay path is provided through which the second portion of the beam travels before reaching the light intensity controlling device. The control voltage is supplied by a variable power supply. The apparatus may be tuned to properly attenuate the laser beam passing through the intensity controlling device by adjusting the power supply, the optical delay path, or the light attenuating means.
50 Citations
21 Claims
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1. An optically controlled laser beam pulse energy regulation apparatus for a pulsed laser beam comprising:
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(a) photodetection means; (b) means for directing a first portion of said pulsed laser beam onto said photodetection means to vary the resistance of said photodetection means in proportion to the energy of said beam; (c) light intensity controlling means through which a second portion of said pulsed laser beam passes; (d) means for integrating the beam energy incident on said photodetection means to generate a control voltage proportional to the beam energy to said light intensity controlling means; and (e) optical delay means through which said second portion of said laser beam passes before entering said light controlling means; whereby a control voltage is applied to said light intensity controlling means which is proportional to the amount of light energy striking said photodetection means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An optically controlled laser beam pulse energy regulation apparatus for a pulsed laser beam comprising:
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(a) photodetection means; (b) beam splitter means for directing a first portion of said pulsed laser beam onto said photodetection means to vary the resistance of said photodetection means in proportion to the intensity of said beam; (c) light attenuation means through which said first portion of said pulsed laser beam passes before striking said photodetection means; (d) light intensity controlling means through which a second portion of said pulsed laser beam passes; (e) an optical delay line through which said second portion of said laser beam passes before entering said light intensity controlling means; (f) means including a variable voltage power supply for passing a control voltage through said photodetection means to said light intensity controlling means; whereby a control voltage is applied to said light intensity controlling means which is proportional to the amount of light striking said photodetection means to thereby change the energy of the laser beam passing through said light intensity controlling means and said apparatus may be tuned to vary the energy of the laser beam passing through said light intensity controlling means by one or more of said light attenuation means, said optical delay line, or said variable power supply. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A process for optically controlling the energy of a pulsed laser beam comprising:
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(a) providing a photoresistor; (b) directing a first portion of said pulsed laser beam onto said photoresistor to vary the resistance of said photoresistor in proportion to the energy of said beam; (c) directing a second portion of said pulsed laser beam toward a light intensity controlling means; (d) producing a control voltage proportional to integrated beam energy incident on said photoresistor and applying the control voltage to said light intensity controlling means; and (e) optically delaying said second portion of said pulsed laser beam before entering said light intensity controlling means;
whereby said control voltage applied to said light intensity controlling means is proportional to the amount of integrated light energy directed onto said photoresistor. - View Dependent Claims (18, 19, 20, 21)
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Specification